Capacitors Blog

Suntan Technology Company Limited
---All kinds of Capacitors

This is a measure of a capacitor's ability to store charge. A large capacitance means that more charge can be stored. Capacitance is measured in farads, symbol F. However 1F is very large, so prefixes are used to show the smaller values.

Three prefixes (multipliers) are used, µ (micro), n (nano) and p (pico):

• µ means 10-6 (millionth), so 1000000µF = 1F
• n means 10-9 (thousand-millionth), so 1000nF = 1µF
• p means 10-12 (million-millionth), so 1000pF = 1nF

Capacitor values can be very difficult to find because there are many types of capacitor with different labelling systems!

There are many types of capacitor but they can be split into two groups, polarised and unpolarised. Each group has its own circuit symbol.

Suntan Technology Company Limited
---All kinds of Capacitors

A capacitor is a passive electronic component that storesenergy in theform of an electrostatic field. In its simplest form, a capacitorconsists of twoconducting plates separated by an insulating material called thedielectric. Thecapacitance is directly proportional to the surface areas of the plates, andis inverselyproportional to the separation between the plates. Capacitance alsodepends on thedielectric constant of the substance separating the plates.

The standard unit of capacitance is the farad, abbreviatedF. Thisis a large unit; more common units are the microfarad, abbreviated µF (1 µF =10-6F) and the picofarad, abbreviated pF (1 pF = 10-12 F).

Capacitors can be fabricated onto integrated circuit (IC)chips. They are commonly used in conjunction with transistors in dynamic random access memory (DRAM). The capacitors helpmaintain thecontents of memory. Because of their tiny physical size, thesecomponents have lowcapacitance. They must be recharged thousands of times per second or theDRAM willlose its data.

Large capacitors are used in the power supplies of electronicequipment ofall types, including computers and their peripherals. In these systems,thecapacitors smooth out the rectified utility AC, providing pure, battery-likeDC.

Suntan Technology Company Limited
---All kinds of Capacitors

In many ways capacitors are the hidden saving grace of the electronics world. They play an essential role in smoothing switch transitions by storing and releasing a small amount of energy over short time scales. Although inductors can play the same role, I think it is safe to say that without small, accurately valued capacitors the modern electronics industry would be a very different beast. Essentially, capacitors store charge, which means that the amount of charge they can store is related to the area available to put said charges. Over recent years, the development of better control over small scale structuring has lead to large increases in capacitance in relatively small packages. The increases have been such that there have been some thoughts of putting these supercapacitors to work as battery replacements in applications where high currents are required.

On that front we can present some good news. Last month Science reported that scientists had observed an unexpectedly large increase in capacitance in some nanoporous materials. A capacitor at its most simple is a couple of parallel metal plates, where the capacitance increases with the size of the plates and as the two plates get closer together. Unfortunately, increasing the area without too much thought is a quick way to find yourself ordering another 19 inch rack for your capacitors, while sparks, ashes, and electrical fires come from the plates getting too close together. However, an alternative is to roughen the surface and include an electrolyte, which effectively replaces the second plate. This increases the surface area of the plates without increasing the volume. The development of nanoporous materials has lead to dramatic increases in the surface area of capacitors and hence a reasonably sized supercapacitor. Exploring nanoporous carbon for capacitance is nothing new, however, previous methods had very little control over the pore size. Here the researchers developed a different fabrication process that allows them to control the pore size to within 0.05nm. The process begins with a carbide substrate, which is a metal plus carbon atoms. They then etch the metal away by reacting it with chlorine, leaving the surrounding carbon structure intact. Since the amount of metal in a carbide depends on the which metal is used, the pore size can be controlled quite accurately by a good choice of metal and the amount of etching performed.

Once the pore size reduced to that below the electrolyte ion plus surrounding solvent molecules , the effect of the pores was reduced. This is because the increased surface area only works if the distance between the electrolyte and plate remains constant and once the pores get too small the charges on the inside of the pore are too far from the nearest electrolyte ion. However, a further decrease in pore size saw the capacitance increase again. It turns out that when the material is so porous, many of the carbon atoms are just barely hanging on. As a result they can move around quite a bit, which allows the electrolyte to squeeze in. The resulting tight fit between the two means that along with an effective increase in surface area, the gap between the two plates is also decreased. Both of these factors increase the capacitance.

I would say the future looked foamy but my glass is empty.

Suntan Technology Company Limited
---All kinds of Capacitors

NIC Components has unveiled a new range of film chip capacitors which are designed to offer stable characteristics over a wide operating temperature range.

The NSMX series of wound, metallised polyphenylene sulphide film capacitors can be used in applications that require low-absorption characteristics.

According to the company, they are suitable for use in power supplies requiring low-loss parameters.

The product has an operating temperature range of -40 degrees c to 125 degrees c and is RoHS compliant.

NSMX series is also compatible with the latest SAC reflow soldering processes up to 260 degrees c.

The firm states that it has very stable temperature, frequency, voltage, bias and dielectric absorption, with ElectronicsTalk stating that this makes them an alternative to other dielectrics such as MLCCs.

Meanwhile, Vishay recently announced the release of three new X2 electromagnetic interference suppression film capacitors, which it claims offer an increased voltage rating while continuing to meet safety approvals.

Rapid Electronics are a leading UK supplier of electronic components, electrical products and industrial equipment to the Assembly Manufacturer sector.

Suntan Technology Company Limited
---All Kinds of Capacitors

Advanced Capacitors World Summit 2009Final program confirmed featuring the latest in industry developments, applications and technology PORTLAND, Maine, January 6, 2009 —IntetechPira, a leading conference and research organization is pleased to announce the final program for the 7th annual Advanced Capacitors World Summit 2009 set for March 31 – April 2, 2009 at the Hilton Torrey Pines in La Jolla, CA, US.

Co-Chaired by Richard Smith, ANA Strategic System Group and Andrew Burke of the University of California Davis Institute of Transportation Studies, this year’s program is designed to help current and prospective users, integrators and suppliers of advanced power systems understand modern energy storage and delivery challenges for power intensive applications and identify business opportunities and realities with adopting advanced capacitors and capacitor hybrid systems to solve application energy requirements. Speakers will discuss the latest market trends and developments, power engineering and integration strategies, design and business implications and costs associated with advanced power systems for various applications, including transportation, automotive, power and consumer electronics and renewable energy.

Market Overview and industry developments:

Bobby Maher of M Cubed Consulting will start off the program with a comprehensive overview of ultracapacitor market trends and technology advancement and David Alexander from IVUS Energy Solutions, creator of the patented FlashPoint Power Technology, will address serious challenges that arise when developing capacitors for the market. Andy Burke of UC Davis will provide an engaging comparison of ultracapacitors and advanced battery technology in terms of performance, cost and versatility, while John Miller of Maxwell Technologies will show how the two technologies can be best applied in tandem. A panel presentation from members of the investment community will conclude the morning session and will provide insight on how to secure funding in uncertain economic times.

John Skibinski of Eaton Corporation will shed light on the growing demand for advanced energy storage technologies for wind and solar applications. Speakers from Volvo Technology Corporation, General Electric and NREL will discuss engineering energy storage systems for hybrid electric vehicles and heavy hybrids. Aerospace applications will be explored with presentations from Lockheed Martin Aeronautics and company partner PC Krause and Associates and additional new and emerging applications will be covered by Jin Song of Nesscap.

Olgierd Paluskinski of the University of Arizona and M Grant Norton of GoNano Technologies will discuss the latest work with improving the energy density of capacitors. Paluskinski will also discuss how his group has used nanotechnology to achieve better performance and reduced cost for photovoltaics applications serving to reduce fluctuations in output power while increasing conversion efficiency. Yuri Maletin of APowerCap Technologies will reveal how nano-engineered capacitors using inexpensive nanoporous carbon material can lead to improved performance, while reducing cost, in automotive, hand-tools, energy quality and power management applications and systems.

Applications and technology:

Additional presentations from ISE Corporation, Ionix Power Systems LLC, Sigma Technologies International, Rockport Capital and Battery Ventures will also be featured.

As one of the worlds leading forums for discussing the latest technical advances and market trends in the EC industry, IntertechPira’s Advanced Capacitors World Summit 2009 is a dynamic industry event, providing a unique opportunity to gain the necessary knowledge and network with global leaders from around the world.

For complete program details and registering options, please visit: www.advancedcapacitorsws.com

Members of the press interested in attending, to find out if you qualify for a complimentary press pass, please contact Press Officer Sheri Bonnell at sheri.bonnell@pira-international.com or +1 207 781 9637.

 Recent advances in electrochemical capacitors for energy storage open new opportunities for water desalination devices with high energy efficiency.

Existing technologies for hard, brackish and sea water desalination are highly energy consuming even in the case of the best available technology nowadays, Reverse Osmosis. In addition to this problem, the construction of desalination plants requires intensive capital expenditures.

Capacitive Deionization is a technological alternative to Reverse Osmosis provided it is a non-membrane and low-pressure process, which are possibly the two main drawbacks of the Reverse Osmosis technology. The Capacitive Deionization concept is schematically represented in the Figure. During the deionization cycle, an external electrical charge is applied on a pair of electrodes introduced in the feed water, this makes the ions dissolved in the water to migrate towards the electrode of opposite charge, where they are adsorbed. In the regeneration cycle, the electrical load of the electrodes is switched off, therefore adsorbed ions are released. If an electrical circuit is connected at this stage, an electrical current will be produced, just like in the discharge of a capacitor.

Early studies almost 40 years ago showed that Capacitive Deionization could be a feasible technology for low-cost water desalination, but by that time appropriate materials were not available yet. However, nowadays with the most recent advances in electrochemical capacitors, there are improved electrodes with performances good enough to bring the Capacitive Deionization systems from research laboratories to real life applications.

A capacitor or condenser is a passive electrical component consisting of an insulating, or dielectric, layer between two conductors. When a voltage potential difference occurs between the conductors, an electric field occurs in the insulator. This field can be used to store energy, to resonate with a signal, or to link electrical and mechanical forces. Capacitors are manufactured as electronic components for use in electrical circuits, but any two conductors linked by an electric field also display this property. The effect is greatest between wide, flat, parallel, narrowly separated conductors.

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Smaller density, four times the capacity, instant recharge... awesomeness.

You smell that? It’s the silicon-enriched aroma of new technology, and the source is nothing short of amazing! A small company in Cedar Park Texas known as EEStor has claimed it has developed a battery that will solve all life’s troubles. Well, all tech enthusiasts’ troubles anyhow.

Anyone who owns, or has owned, a portable device is familiar with how irritating battery technology is. Not only does it take hours to recharge the battery, but the capacity is often mediocre at best. Furthermore, they degrade over time and their charge is lost at a rate of several percent each month. The likes of NiCad, Li-ion, NiMH and Li-Po (to name a few) all suffer these cruel flaws, and are commonly found in everything from MP3 players to notebook computers. Fortunately for consumers, a new battery technology is emerging. One that will make power issues a thing of the past – the supercapacitor.